Arizona, California, Florida and Nevada -- the states that were most hurt in the real estate collapse over the past five years -- are now leading the U.S. labor market expansion. The four states added 222,100 jobs from August through December, accounting for 28 percent of the increase in U.S. employment in that period, according to Labor Department figures. Their outperformance may continue, say economists at Moody’s Analytics Inc. and IHS Global Insight.